1. Field of the Invention
This invention relates to an apparatus for storing and retrieving microfilm images stored on cards of film known as microfiche cards, and in one aspect to an improved apparatus for extracting the card from the storage position and positioning the same at a viewing station and returning the card to its storage position.
2. Description of the Art
Machines for storing microfiche cards and for the retrieval of the microfiche cards to display individual images and project the same either on a screen, make a hard copy of the image, or position the microfiche such that a video signal may be generated by scanning the film for projection on a remote terminal are known. Examples of patents disclosing microfiche retrieval systems of the type addressed herein are U.S. Pat. Nos. 3,429,436, issued Feb. 25, 1969, to E. H. Irasek; 4,190,899, issued Feb. 26, 1980, to D. H. Smith et al; and 4,273,427, issued June 16, 1981 to D. C. Bailey. Numerous additional patents exist relating to devices for scanning microfiche cards or other microfilm image-supporting media such that the information on the microfilm image may be retrieved and reread by a projection image or by duplication on a CRT terminal. Examples of such devices are illustrated in U.S. Pat. Nos. 3,753,240, issued Aug. 14, 1973 to Roy L. Merwin; and 3,604,850, issued Sept. 14, 1971 to R. R. Eckenbrecht et al.
These systems provide a means for storing information which must be stored on a photographic medium and retrievable automatically by suitable coding logic stored in a computer. The actual storage and retrieval device will respond to the signals to rotate the storage file to locate the predetermined microfiche card at the retrieval opening such that it may be removed from the file and a specific image on the card positioned for reading the image either by projection, by scanning, or by copying.
The present invention thus deals with the file for storing the microfiche cards, accessing the microfiche cards to a card-handling mechanism for picking the cards from the file and operable on an XY axis to orient a specific image on the card at the film reading station, for moving the card to position another image at the film reading station and then to the structure for reinserting the microfiche card in the file, delivering the card to the operator through an opening into the file, or dumping the card from the file. The mechanism utilized for storing the microfiche card comprises a pair of trays, fixed on a rotatable axis and positionable to place a given one of the storage slots in one or the other of the trays at the access opening. Picker fingers then grasp the microfiche card, lift the card slightly off the tray, straighten (by tensioning) the leading edge of the card and withdraw it from the file. Separators for separating the adjacent cards from the selected card aid the fingers to grasp the microfiche card and position the card at the viewing station. Thus, the visual patterns stored in the microfiche card can be optically scanned to convert the image pattern electrically to signals which by analog-to-digital conversion and speed conversion are transmitted to remote terminals along with alphanumeric data for review by an operator. The equipment of this invention will make visual patterns stored on-line in a control system totally computer driven and accessible. When the information has been viewed the microfiche card is reinserted into the slot in the tray and the separators for the adjacent microfiche cards are returned to their normal position and the tray carousel is rapidly indexed to locate the next microfiche card called for by the computer.
During insertion of the microfiche cards, which are four to eight mils in thickness and quite susceptible to bending or buckling during mechanical handling of the microfiche cards, the cards may become damaged or destroyed. It is therefore important the equipment handle the cards in such a manner as to sense if some abnormality exists in the card or in the operation of the equipment such that the card may be reinserted without being forced, if in fact, the card approaches the storage slot and strikes an obstruction causing it to be slightly bent, bowed, or bucked.
It is thus important to the present invention that the microfiche cards be inserted into the storage and retrieval system by the machine such that all of the handling of the card is carried out by the machine, including the loading of the microfiche into the carousel trays, taking a card from the tray and positioning it at the viewing aperture and returning the card to the storage tray or returning the card through a load-unload slot to the operator. To accomplish this purpose, a novel microfiche card transport system is provided for moving the card in a plane with respect to the carousel and with respect to the load-unload slot and with respect to the viewing aperture. Thus the present invention provides a mechanism for loading a card presented to the system at a load slot and precisely positioning the microfiche card in a slot in the storage tray and being able to retrieve the card from the storage tray and move it in an XY coordinate plane to the viewing station to precisely position an image bearing frame of the microfiche at the viewing station, to discharge the card from the storage system or to return the card to its position in the storage tray.